surely they can't cut off exploring the world for some linear shyt
I don't think they will. They've said that the game is so massive, it's filled up TWO blu-ray discs.
---
People are skeptical, but there's actually a ton of things that were supposed to be in the OG FF7 that never made it. Now they have the opportunity to flesh things out like they've always wanted to, like AVALANCHE for example. Why not take advantage of the opportunity? The argument is "Midgar was so small, why are they fleshing it out to be longer?" when they have no idea what's planned. Midgar is supposed to be an enormous city, there's so many things they can do with the location, so much lore they could add, it's silly to think that they're just gonna make the plot pacing slow down to a crawl on two discs just for the sake of money. Think about it, how would that NOT blow up in their faces?
Also, just because Midgar is this massive, it doesn't mean that every single location is going to be the same size. It's not like they're gonna turn Kalm into Los Angeles, Midgar at least has a logical reason for being that big. Places like Gongaga and Nibelheim are probably going to be fleshed out more, but probably around the same as how it was in Crisis Core. Cosmo Canyon might be huge, but that's justified too. Cosmo Canyon though isn't gonna take up anywhere near the amount of space.
Honestly, I wouldn't put too much stock into "they don't know how many games there will be", they're only saying this because as bad as it looks... It'd be even worse if they say "Only two or three games will come out", and then have to come out later and say, "Sorry, we have to add another volume, in order to complete the story." If they're in the planning stages for Part 2, that means they more than likely already have a ballpark estimate of how many games this will take, and I'm willing to guess that they're aiming for three. Also to keep in mind too, the PS5 is most likely dropping 2020 and may very well have a much bigger capability of reading blu-ray discs that have a much higher capacity. Meaning, you probably won't need 2+ discs on each release, just one (theoretically).
People feel skeptical, but all of this will be cleared once they nail Part 1. Square Enix hasn't delivered too well lately, and so the consumer trust isn't there. If this were, say, a company like Naughty Dog that people believe in, then I think the split parts would've been more welcomed. And honestly, I welcome it as well. I want this to be the best possible experience, why rush to have it in my hands all at once? Look at how alive the FF community is ever since the State of Play trailer, imagine it being this exciting for the next foreseeable future? I believe in the team, they know full and well just how important this remake is and what the stakes are. They've delivered on everything and have clearly surpassed everyone's expectations so far, so there's no reason to start doubting them now.